Chapter 3, Problem 25P

* Spider-Man Spider-Man holds the bottom of an elevator with one hand. With his other hand, he holds a spider cord attached to a 50-kg box of explosives at the bottom of the cord. Determine the force that the cord exerts on the box if (a) the elevator is at rest; (b) the elevator accelerates up at $\text{2}{\text{.0 m/s}}^{\text{2}}$; (c) the upward-moving elevator's speed decreases at a rate of $\text{2}{\text{.0 m/s}}^{\text{2}}$; and (d) the elevator falls freely.